Final Word About ‘50% of Smokers are Killed by Tobacco’

Something has been nagging in my mind all day and has only ‘come to the surface’ in the last few hours. Let me quote this para from the final report on the Doctors Study:

For those born in 1900-1909, annual mortality among non-smokers was, both in middle and in old age, about half that among cigarette smokers. (These twofold death rate ratios are calculated from the logarithms of the probabilities of surviving from 35-70, 70-80, and 80-90 in figure 2 (top graph).) Taking, as before, the excess overall mortality among these smokers as an approximate measure of the excess mortality actually caused by smoking, this twofold ratio indicates that about half of the persistent cigarette smokers born in 1900-1909 would eventually be killed by their habit.

Unfortunately, I cannot copy and paste the figure referred to, but it is very similar to this one:


[The grid-lines are mine]

(As an aside, if you look carefully, there is a dotted line which moves beyond the continuous line. The dotted line represents people who stopped smoking. As you can see, the fact that the dotted line is on the right of the continuous line shows that ex-smokers lived longer than non-smokers! Curious…..)

The right-hand line is non-smokers: the left-hand one is smokers.

The text that I have quoted says that, to calculate the 50% ‘killing by tobacco’ figure, ‘the logarithms of the probabilities…’ of both smokers and non-smokers was used.

What has been niggling me has been the question of why the fortunes of non-smokers should be involved.

Imagine an army which consisted of combatants and non-combatants. The non-combatants are well behind the lines and consist of cooks, doctors, drivers, etc. Suppose now that battle take place and some of the combatants are killed, some wounded and some unscathed, and it was desirable to find out the distribution of deaths and wounds among the combatants, as to rank (regarding the number of leaders you have lost), job (such as machine gunner, rifleman, etc). In what way would the NON-combatants need to figure in your calculations?

Applying that idea to the question of smoker deaths, we might regard non-smokers as ‘non-combatants’. Non-smokers figure in calculating differences between smokers and non-smokers, but not in calculating the fates of smokers alone.

In effect, what seems to have happened is that the fate of non-smokers was taken as ‘the ideal’ (aka ‘The Standard Human Being!’). Doll et al used ‘non-combatants’, who were not exposed to ‘killer tobacco’, to decide what the ideal rate of death distributions among smokers should be.

Does that make sense to you? It doesn’t to me, regardless of what mathematical formulae were used.


Looking at the graph above, it would be hard not to conclude, at first sight, that, compared with non-smokers, ALL smokers were killed by tobacco. That would be wrong. It is easy to overlook the fact that lots and lots of non-smokers died before smokers – the graph shows it! For example, at the age of 70, 20% of non-smokers were dead, and 60% of smokers were still alive. No wonder that Doll et al had to use ‘logarithms of probabilities’ to fake the figures!


Finally, I don’t think that it is possible, by any method, to use data from the Doctors Study to make claims about what percentage of smokers are ‘killed by tobacco’ (back to the ‘combatant/non-combatant situation).  But is there any way to assess that percentage?

I suppose that there is. What you would have to do is conduct lots and lots and lots of autopsies looking for traces of tobacco. By ‘traces of tobacco’, I don’t mean actual bits of tobacco smoke (although asbestos-related lung cancer does have such physical evidence). I mean some sort of chemical trail. It is extremely odd that such a trail has not been discovered since experiments on mice and rats and such MUST have involved subjecting them to very concentrated tobacco smoke  and then killing them and subjecting their lungs to microscopic examination. In fact, we know that this has been done. The probability is that batches of thousands of mice have been bred, subjected to copious tobacco smoke, and slaughtered at different ages and stages, and their lungs microscopically examined for changes. We can reasonably assume that that has been done because such practices are the only way in which mice can be ‘genetically engineered’ to be susceptible to cancers.  That is, you breed mice, find out which ones get cancer and then breed the offspring of those mice, and do it again and again. You liquidate the rest, or use them in some other experiments. What’s the problem?

The problem is that the experiment has never worked. The genetically engineered mice fared no worse, when subjected to tobacco smoke, than did other genetically engineered mice, in the same batch, which were NOT subjected to tobacco smoke. They all got cancers at much the same rate.

Human autopsies of that nature have been done, but, as far as I know, no such traces of ‘carcinogens’ have been found.

So what happens to a specific micro-particle of tobacco smoke enters a human lung? Where does it go? Why do such lungs, when examined under a microscope, not reveal masses of micro-particles? Where do they go? The answer must surely be that they dissolve into molecules and are carried away in the blood-stream and excreted. You would think, from the dissertations of tobacco control that human lungs are delicate, but the truth must be that they are hardy and tough, otherwise the human race would not have survived. I put that point to a anti-smoking professor who favours e-cigs and snus as reducers of ‘tobacco harm’, but he did not permit its publication.

How hardy and tough are human lungs?


This post is getting rather long, but I must persevere.

Rose produced this gem, being a statement from Doll:

Doll R. Commentary: the age distribution of cancer and a multistage theory of carcinogenesis – 2004.

“What I now find surprising, now that the concept of multiple mutations is so widely accepted, is that so many people fail to see that it accounts for the fact that only a relatively small proportion of people (<20%) are commonly victims of a particular type of cancer even if heavily exposed to known chemical carcinogenic agents. There have been two small groups of men who were very heavily exposed to chemical carcinogens in the course of their work in which all were affected, but they are atypical.

The fact that only, say, 20% of heavy cigarette smokers would develop lung cancer by 75 years of age in the absence of other causes of death does not mean that 80% are genetically immune to the disease any more than the fact that usually only one cancer occurs in a given tissue implies that all the stem cells in the tissue that have not given rise to a malignant clone are also genetically immune.

What it does mean is that whether an exposed subject does or does not develop a cancer is largely a matter of luck: bad luck if the several necessary changes all occur in the same stem cell when there are several thousand such cells at risk, and good luck if they do not.

Personally, I find that makes good sense, but many people apparently do not”

You can see from that statement that, even though Doll was a communist eugenicist who wanted to destroy the tobacco industry, he still retained an element of common sense. That does not really ‘gel’ with the final report on the Doctors Study. I doubt that Doll had much to do with it. That reinforces my thinking that the final report was propaganda driven. All the stuff about “50%” is propaganda, supported by doubtful mathematical mumbo-jumbo, as we have seen.


We can conclude that the slogan (or mantra, or sound-bite) “Tobacco kills 50% of its users” has no foundation. But what ‘counter slogan’ can we think of?

Let us think about the proportions of smokers/non-smokers who are killed by tobacco related ‘diseases’. 84% of non-smokers died from tobacco related diseases, while 85% of smokers were killed likewise. The additional 1% might be just ‘noise’ (statistical uncertainties). Thus, as many non-smokers die from tobacco related diseases as do smokers. Thus, while there might be a time-lapse, the final result is the same.

Perhaps the answer to the claim “50% of smokers are killed by tobacco” is, “Rubbish! Just as many non-smokers die from ‘tobacco related diseases’ as do smokers. The Doctors Study proved it”. The implication there is that the percentage of people who die from smoking is the same as that from not smoking.


Our lungs are tough and hardy, just like perennial plants and trees. They are not delicate, like annuals. Tobacco plants are annuals, as they have been ‘genetically engineered’  in the past century or two. Their seeds must have either over-wintered or been perennial in the past, otherwise they would not exist. It may well be that today’s tobacco plants are unnatural.


What slogan counters “50% of smokers are killed by tobacco”?






21 Responses to “Final Word About ‘50% of Smokers are Killed by Tobacco’”

  1. Rose Says:

    Why do such lungs, when examined under a microscope, not reveal masses of micro-particles? Where do they go?

    Lovely picture of one stretching it’s arms to grab particles.

    Anatomy and Function of the Normal Lung

    “If an irritant does enter the lung, it will get stuck in a thin layer of mucus (also called sputum or phlegm) that lines the inside of the breathing tubes. An average of 3 ounces of mucus are secreted onto the lining of these breathing tubes every day. This mucus is “swept up” toward the mouth by little hairs called cilia that line the breathing tubes. Cilia move mucus from the lungs upward toward the throat to the epiglottis. The epiglottis is the gate, which opens allowing the mucus to be swallowed.”

    “Another protective mechanism for the lungs is the cough. A cough, while a common event, is also not a normal event and is the result of irritation to the bronchial tubes. A cough can expel mucus from the lungs faster than cilia.”

    • junican Says:

      Thanks for those links, Rose – fascinating stuff.
      If you scroll down to the bottom of the first link, there are two time-sequence videos of macrophages digesting material.

  2. harleyrider1978 Says:

    Human lungs ‘brush’ themselves clean of contaminants
    Friday, September 07, 2012 by: David Gutierrez, staff writer

    Human lungs contain a tiny network of constantly moving “brushes” that flush contaminants out of the respiratory system, according to research conducted by scientists from the University of North Carolina and published in the journal Science.

    Scientists have known for a long time that the respiratory system protects itself by means of a coating of mucus, which is sticky enough to trap pollutants and keep them from reaching the body’s cells. When needed, the body can expel this mucus through a runny nose or a cough.

    “The air we breathe isn’t exactly clean, and we take in many dangerous elements with every breath,” said lead researcher Michael Rubinstein.

    “We need a mechanism to remove all the junk we breathe in, and the way it’s done is with a very sticky gel, called mucus, that catches these particles and removes them with the help of tiny cilia. The cilia are constantly beating, even while we sleep.

    “In a coordinated fashion, they push mucus, containing foreign objects, out of the lungs, and we either swallow it or spit it out. These cilia even beat for a few hours after we die. If they stopped, we’d be flooded with mucus that provides a fertile breeding ground for bacteria.”

    But until now, researchers have never understood why the mucus does not stick to or even infiltrate the respiratory cells themselves. The foremost theory, known as the “gel-on-liquid model,” posited that an as-yet-undiscovered watery “periciliary” layer kept mucus and cilia separate. The problem with this theory was always that to the best of scientific knowledge, mucus should eventually dissolve into such a watery layer, not remain separate.

    “We can’t have a watery layer separating sticky mucus from our cells because there is an osmotic pressure in the mucus that causes it to expand in water,” Rubinstein says. “So what is really keeping the mucus from sticking to our cells?”

    To get to the bottom of the mystery, the researchers used modern imaging techniques to examine the interior of the lungs. They found a dense network of brush-like structures that sit atop the cilia. These brushes are composed of protective molecules that keep both mucus and contaminants from getting to the respiratory cells beneath. These molecules also function as a second line of defense against viruses or bacteria that manage to penetrate the mucus.

    Stephen Spiro of the British Lung Foundation said the findings could help significantly improve scientific understanding of lung function.

    “Mucus has a complex biological make-up and forms a vital part of the lungs’ defense mechanism,” he said.

    “Research such as this helps our understanding [of] how this system works, and of the complex mechanisms deep within our lungs which protect us from the atmosphere we breathe in.”

    Rubinstein and his fellow researchers noted that their findings may also explain previously mysterious lung disorders from asthma to cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD). These diseases may stem from a collapse of the protective brushes.

    “We found that there is a specific condition, below which the brush is healthy and cells are happy,” Rubinstein said. “But above this ideal condition, in diseases like CF or COPD, the brush becomes compressed and actually prevents the normal cilia beating and healthy flow of mucus.”

    In such conditions, the mucus would then stick directly to the lung’s cells.

    “The collapse of this brush is what can lead to immobile mucus and result in infection, inflammation and eventually the destruction of lung tissue and the loss of lung function,” Rubinstein said. “But our new model should guide researchers to develop novel therapies to treat lung diseases and provide them with biomarkers to track the effectiveness of those therapies.”

    Sources for this article include:

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  3. harleyrider1978 Says:

    Learn more:

  4. garyk30 Says:

    What slogan counters “50% of smokers are killed by tobacco”?

    100% of all people die without regard to their personal habits.
    What is said to ’cause’ their death is of no importance as it weill always be one thing or another.

    • garyk30 Says:

      If smoking only kills half of the smokers, that means that half of the smokers are not harmed by their smoking.

      What is it that harms and kills 100% of the never-smokers?

    • garyk30 Says:

      Does that include ex-smokers?
      Quitting is supposed to save them.

    • beobrigitte Says:

      Lol, Gary. You were quicker than I was!!!

      My slogan would be:

      Life kills 100% of people. Regardless.

    • junican Says:

      How about:
      “Tobacco kills ALL its users; alcohol kills ALL its users; eating too much kills ALL those who eat too much; sugar kills EVERYONE who takes sugar in their tea or coffee. There is no escape”

  5. garyk30 Says:

    Doll’s doctors study proved that 84% of never-smokers die from the diseases caused by smoking.

    Since only 50% of smokers die from their smoking, smoking must prevent deaths from those diseases.

  6. Rose Says:

    Incidentally, if you are watching the Tour de France tomorrow watch out for Pool, Otley, Burley in Wharfedale and Ilkley on the route from Harewood.

    They have gone absolutely daft with decorations, it’s quite a sight to behold.
    There have been yellow painted bikes appearing in the hedgerows for what seems like weeks and now everywhere is awash with bunting.

    • beobrigitte Says:

      Yeah, – I am not into peddling a bike as I have done this for a long time in my life as a means to get from A to B.

      Rose, I am not watching people on bicycles. The whole thing is a hype and whilst the ones doing this sport enjoy it being “important”, it fails to appeal to me.

      I tolerate the bicycle craze – are they tolerating me?

      • Rose Says:

        I appreciate your sentiments Brigitte, but even though I have no interest in cycling it will be fun to watch it going past my favourite garden centre, on past the butcher and very close to the cake shop. : )

      • junican Says:

        I think that I would agree with Rose in this case, Beo. If ‘le tour de France’ passed along the A6, very near where I live, I would most certainly walk up to the roadside and watch the cyclists go by.

        But I would not cheer.

      • Rose Says:

        I will be watching on TV, I want to see what my area looks like from the air.

        If I wanted to watch the race go by I’d have had to be there by 4 am as that was when the roads closed.

  7. Frank Davis Says:

    From your Doctors Study quote:

    …half of the persistent cigarette smokers born in 1900-1909 would eventually be killed by their habit.

    So it only applies to people born between 1900 and 1909.

    There can be hardly anybody born between 1900 and 1909 alive today, so this ‘half of all smokers are killed by their habit” claim no longer applies to anybody.

    • junican Says:

      Not that simple, Frank. The Report goes on to look at the next decade, people born between 1910-1919, and concludes that things were getting worse. It then moves to the next decade, 1920-29, where things were even worse. Since the Doctors Study started in 1951, people who were born in that decade were the last doctors to join the study (apart from a few younger ones). Things were getting even worse. Thus, the report drew the conclusion that as much as two thirds of smokers ‘were killed by tobacco’, but, I suppose, the propaganda machine decided that 50% was good enough to induce the propaganda effect, and was nice and simple, and suitable for SHOUTING.

  8. The 50% Claim Debunked | Frank Davis Says:

    […] Junican may have found the source of the “50% of smokers are killed by their habit” claim. From the final report of the British Doctors study (anyone got a link to the 2004 report?): […]

  9. T-NM (@smofunking) Says:

    As with most anti-smoking surveys, smokers are treated as a single entity and not as individuals. A one a day smoker is treated no differently to a 60 a day smoker and all we get is a one statistic fits all conclusion.
    Is there actually a criteria for who is classed as a smoker? I remember reading that someone was asked by a member of hospital staff whether a recently deceased relative had ever smoked and when informed that they had done but stopped some 30 years ago, they were still classed as a smoker.
    I also recall reading that anyone who has smoked more than 10 cigarettes in their lifetime was also deemed to be a smoker and were therefore eligible to be classed as a smoking related death.
    If this is the case then all these statistics are worthless.

  10. Final Word About '50% of Smokers are Killed by ... Says:

    […] For those born in 1900-1909, annual mortality among non-smokers was, both in middle and in old age, about half that among cigarette smokers. (These twofold death rate ratios are calculated from the logarithms of the …  […]

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